In the latest data to be presented at this year's the Health Protection Agency annual conference, delegates will be informed that the number of cases of the mosquito-born Chikungunya virus detected in travellers returning from the Indian Ocean has significantly increased during 2006.

This increase is due to an outbreak in the islands of the Indian Ocean. Therefore it is important that GPs and healthcare providers continue to be aware that this is one of a number of diseases that travellers can contract. It is important that people take sensible measures to minimise any risk.

Since March 2005 the number of cases of Chikungunya fever have been increasing in the islands of the Indian Ocean, particularly the island of Reunion. The latest data will show that the number of travellers returning to the UK with evidence of exposure has risen to 93 as of August this year, up from an average of 6 cases in previous years.

The virus is spread by the bite of a mosquito and causes a non-fatal self limiting illness characterised by a high fever with headache, severe joint pains, and a rash with nausea and vomiting. The symptoms usually appear between 4-7 days after being bitten and can persist for several weeks. There is no vaccine against Chikungunya and treatment consists of relieving symptoms by using pain killers and ensuring that people take plenty of fluids and rest. Acute symptoms last from a few of days to a couple of weeks whilst some patients have reported incapacitating joint pain for up to several months.

Sir William Stewart Chairman of the Health Protection Agency (UK) said " Although previously centred on the islands of the Indian Ocean ( Mauritius , Madagascar and the Seychelles ), cases in this region are declining whilst cases from mainland India are increasing. This is due to an ongoing outbreak occurring on the mainland, with over a million suspected cases to date. Therefore it is important that travellers to the region follow the usual health advice on how to avoid being bitten by mosquitoes and other insects. This involves the use of insect repellents and wearing long trousers / long sleeved shirts, particularly during daylight when mosquitoes of the Aedes species tend to be most active."

Information on avoiding insect bites is available on the NaTHNaC website at - nathnac/pro/factsheets/iba.htm